Vahiable colfdeirseb



Aug. 2, 1927e 1,637,646 y H. KIMURA VARIABLE CONDENSER Filed Jan. 7,1925 2 Sheets-me?, 1

IN EN TOR. ,H/sA/ch' KIM UBA BY Mw.

A TTORNE YS.

Aug. 2, 1927.

H. KIMURA VARIABLE coNDENsER Filed Jan. '7, 1925 2 Sheets-Sheet 2INVE/vzoR. H/sA/CH Kaw/ 2.4 BY

A TTORNEYS.

Patented Aug. 2, 1927.`

.i UNiTED STATES Partnr OFFICE.

HISAICH KIMURA, F LOS NGELES, CALIFORNIA.

VARIABLE oonnnnsnn.

Application filed VJanuary 5 term in that it embodies a vcli-electricelement which has direct contact with the plates or conducting elementsof the condenser to the exclusion or" air, and in suchmanner that thearea of contact between the elements can `be varied at will to eiii'ecta variation in the capacity of the condenser. Y 4

It is also a purpose of my invention to provide a variable .condenser ofthe above described character in which one of the con` 'ducting elementshas rolling Contact with the cli-electric element in effecting avariancein the area of contact between the elements whereby the possibility ofinjury to the cli-electric usually caused by friction between theelements is entirely eliminated.

A further purpose of my invention is the provision of a variablecondenserrin which the elements thereof are arranged to preventreduction of body capacity and to permit a small variance in thecapacity by increasing or decreasing the pressure between' certain ot'the elements.

`I will describe only one form of variable condenser embodying myinvention and will then point out the novel features thereof in claims.n y .e

. In the accompanying drawings,

Figure l is a vertical sectional view taken on the line 1-1 of Figure 2;

Figure 2 is a diametrical section taken on y the lline 2-2 of Figure 15y Figure 3 is a View showing the inner side of the condenser; f .y Y

Figure 4 is a view similar to Figure 2, with parts of the condenserinelevation;

Figure 5 is adetail perspective view oi' the stationaryconductingelement embodied `in the condenser.

Referringspecitically tothe drawings, in which similar referencecharactersreier to similar parts in each of the views, my invention, Ainits vpresent embodiment, comprises a stator or stationary body l5`formed of insulating material and adapted to be secured to the outerside of a panel 16 c0nstituting a portion of the casing .for aradioreceiving set. In the -present'instancea I have` shown tubular studs'lVextending into A the panel 16 and interiorly threaded to receivevscrews I8 which extend through the stator lfywith their heads disposedin con= 7, 1925.V Serial No. :1,067.

ducting cups I9 reposing within suitable.

pockets termed in the stator. The screws I6 co-operaterwith vnuts 20enteriorly threaded on'the stud 17 in securing the stator as a unit tothe outer `side of, thepanel.y The studs l? also receive bindingscrews2l to` which Yconductors (not shown) to be connected. y

The stator l5 in the present instancefis of disk form, and mounted uponits periphery are adapted is a split annulus22 formed of copper orother,y suitable material and which constitutes the stationary conductingelement of the condenser. is shown invFlgures l and 5, this conductingelement is provided .with an extension 23 projecting into a.` suitableslot :formed in thestator l5 for contact with one oi the conducting cupsVl9iso as to provide an electrical connection between the conductingelement and the corresponding screw 18. Surrounding and .contiguoustothe `stationary conducting element is a split annulus 24 formed ofmica and constituting the dielectric oit the condenser. Thismicafannulus ,dial 32connected to :the khandle through the medium ofanan'nular flange 38. t It is tofbe understood thatjthefflange and dialare formed ot insulating material, and that the i threaded collar 29 ismountedin the liange, as clearly shown in `Figures2 and t. The rotor asaunit is rotatably `mounted on the stator and, to this end a stub axle 34extends axially through the stator l5 and is rotati ably'held by meansof a nut 35 threadedly engagingthe stub axle and disposed within asuitable recess formed on the linner side of the stator. The stub axleis of such. length that it pro'ectsfrom the stator and is tixedlyreceivedwithiifi a suitable opening 36 formed in the rotor,` whereby therotor is rotatably supported,

vis in the form of a strip with its ends 24a extending into a suitableslot formed in the The hub 26a of the gear or pinion Q6 hasattachedthereto one end of a strip orribbon 37 of copper whichconstitutes the movable conducting element of the condenser, the otherend of the stripbeing secured between the iii-turned ends 2li of thecli-electric and,

having electrical contact with the other conducting cup 18 so as to beinelectrical communication with the corresponding loindiiig Vscrew 2l.

In practice, the stator of the condenser may be readily applied to andfirmly secured upon the outer side of the panel 16, a cover plate 38being interposed between the panel andstator, as clearly shown in Figure2. In Figure l I have shown a cli-electric 37 com- ,pletely unwound fromthe hub 26, which in reality constitutes a reel, so that substantiallyits entire length is in direct contact shank 27 as a center, therebywindingupon itself the movable conducting element 37. As the movableconducting element is wound upon the hub 26, it will be manifest that itis moved out of contact with the dielectric 24, thus operating to reducethe ca- 'p'acity of the condenser in direct proportion to the amount ofthe conducting element moved out of 'Contact with the cli-electric. Itis to be understood that by reversing vthe rotation of the rot-or, thevmovable conducting element can be unwound from the gear 26 and rewoundupon the stator 15, whereby it will be seen that the contact'area of theconductor 37 with respect to the dielectric 24 can be varied at will,thus securing any capacity desired within the range of the instrument.

If it is desired to secure an extremely fine adjustment ofthe capacity,such adjustment can be obtained by an adjustment of the screw head 28 toincrease or decrease the friction between the conical portion 30 and thehub of the gear 26 which operates 'to vary the contact pressure betweenthe movable conducting element and the cli-electric, it being understoodthat as the friction is increased the conducting element will beslightly shortened :in llength so that dur-ing the winding thereof aboutthe stator it -will more snugly engage the cli-electric to increase thepressure exerted thereon.

From the foregoing operation, taken in conjunction with thevaccompanying drawings, it will be manifest 'that I have provided acondenser in which the variation in capacity is not obtained by changingthe air gap between the conductors, nor by any variation in pressurebetween the two conductors to obtain the major variations in capacity.On the contrary, the variation in capacity is obtained solely by varyingthe con- 'tact'area of the movable conducting element with respect tothe cli-electric. Conse quen'tly, fthe `efliciency of the condenser isuniform throughout its rated range of capacity. Further, the rollingcontact of the ymovable conducting element with rcspectto the`'di-electric permits the variation in contact area vwithout anyVfriction beingset up `between `the di-electric and conducting elenient,thereby preventing any damage to the 'mica and thus indefinitelymaintainingthe originalrange of-capacity. Itis to be further noted thatthe conductors of the condenser are disposed in parallelism with respectto the axis of the dial so that their active surfaces are not parallelto the surface of the dial, asin the usual condensers, whereby theproduction of body capacity from the operators body or hand is entirelyeliminated.

Although Iliave herein shown and described ronly one 'forni of variablecondenser embodying my invention, it is to be understood that variouschanges and modifications may be made therein without departing from thespirit of the invention -and the spirit and scopeof the appended claims.

I claim as my invention:

l. A variable condenser comprising a stan tion'ary conducting' element,an annular dielectric surrounding and contacting withthe conductingelement7 a flexible conductingelement, a rotatable member about whichthe flexible conducting element is normally wound, means by which 'therotatable member is movable bodily and concentrically about thecli-electric, and means for rotating the member about its 'own axis whenbodily rotated by said means to wind or unwind the ve'xible conductingelement on or off of the cli-electric according as the member is bodilyrotated in one direction or the other.

2. A variable condenser as embodied in claim l wherein the last meanscomprises a gear fixedly associated with the cli-electric, and agearfixed to the rotatable member.

3. A variable condenser as embodied in claim l wherein the last .meanscomprises a gear 'xedly associated with the cli-electric, a gear fixedto the rotatable member, and. a dial mounted for rotation and connectedto the last mentioned gear for bodily rotating lthe latter.

4. A variable condenser comprising a stator of disk form, a conductingelement on the periphery of the stator, a cli-electric se.- cured fonthe conducting element, a second conducting element secured at one endto the stator, afgear fixed to the stator, a rotor element, 'and asecond gear rotatably mounted on 'the rotor element, meshing with therst gear and connected to the other end of the second conductingelement.

5. A variable condenser as embodied in claim t wherein the mounting forthe second gear comprises a screw including a sha-nk, a head threadedinto the rotor element, and a conical portion connecting the head andshank, the gear being journaled on the shank and conical portion.

6. A variable condenser comprising a stator having slots therein, astationary conducting element of annular 'form mounted on the peripheryof the stator and having an extension extending into one of said slots,

a di-electric of annular form having exten` sions yextending' into theother slot of the stator and surrounding and contacting with theconducting element, a movable conducting element comprising a strip ofconducting material secured at one end between the ends of thedielectric, and means by which the second conducting element can bewound on or unwound from the cli-electric to vary the capacity of thecondenser.

7. A varia-ble condenser comprising a stator having slots therein, astationary conducting element of annular form mounted on the peripheryof the stator and having an extension extending into one of said slots,a di-electric of annular form having extensions extendinginto the otherslot of the stator and surrounding and contacting with the conductingelement, a movable conducting element comprising Va ,strip of conductingmaterial secured at one end betweenV the ends of the cli-electric,V arot-or mounted for rotational movement on the stator and including adial, a reel rotatably mounted on the rotor and to which the other endof the movable conducting element is secured, and means operativelyconnecting the reel and the stator whereby upon rotation of the ro.- torin one c irection or the other the reel will be rotated bodily and aboutits own axis to wind or unwind the movable-conducting element thereonand to thus vary the areaof contact between the conducting element andthe di-electrio.

8. A variable condenser comprising a stationary conducting element', a idielectric surrounding and contacting with the conducting element, aflexible conducting' element, a rotatable member about which theflexible conducting element is normally wound, means by which therotatable member is movable bodily about the di-ele`ctric,'

and meansfor rotating the member about its own axis when bodily rotatedby said means to wind or unwind the flexible conducting element on oroff of the dielectric according as the member is bodily rotated in onedirection or the other.

HrsAroH KIMURA.

